2003 LEXUS LS430 horn

a. Check the resistance of the HORN fuse.
Standard: Below 1 ohms
If the result is not as specified, replace the fuse.
Fig. 4: Inspecting Fuse (Horn)

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
2.INSPECT HIGH PITCHED HORN ASSY
a. Check operation of the horn.
OK:
HIGH PITCHED HORN ASSY TABLE
Measurement ConditionSpecified Condition
Battery positive (+) --> Terminal 1, Battery negative (-) --> Horn bracketHorn sounds

Fig. 5: Inspecting High Pitched Horn Assy
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
If the result is not as specified, replace the horn assy.
3.INSPECT LOW PITCHED HORN ASSY
a. Check operation of the horn.
OK:
LOW PITCHED HORN ASSY TABLE
Measurement ConditionSpecified Condition
Battery positive (+) -> Terminal 1, Battery negative
(-) -> Horn bracketHorn sounds

Fig. 6: Inspecting Low Pitched Horn Assy
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
If the result is not as specified, replace the horn assy.
If all the check results are as specified above and the wire harness is normal, replace the horn button
switch (steering wheel pad) (see REPLACEMENT
).
REPLACEMENT
1.REMOVE LOW PITCHED HORN ASSY
a. Disconnect the connector.
b. Remove the bolt and horn.
2.REMOVE HIGH PITCHED HORN ASSY
a. Disconnect the connector.
b. Remove the bolt and horn.

Fig. 7: Removing LO/HIGH Pitched Horn Assy
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
3.INSTALL LOW PITCHED HORN ASSY
a. Place the stay onto the baffle part in the radiator support upper, and then install the horn with the
bolt.
Torque: 20 N.m (204 kgf.cm, 15 ft.lbf)
b. Connect the connector.
4.INSTALL HIGH PITCHED HORN ASSY
a. Place the stay onto the baffle part in the radiator support upper, and then install the horn with the
bolt.
Torque: 20 N.m (204 kgf.cm, 15 ft.lbf)
b. Connect the connector.

HINT:
Disconnect the battery negative terminal with the steering column assy extended.
Be sure to extend the steering column, otherwise the steering column cover cannot be removed.
5.PLACE FRONT WHEELS FACING STRAIGHT AHEAD
6.REMOVE SWITCH & VOLUME CASE (SEE OVERHAUL
)
7.REMOVE STEERING WHEEL COVER LOWER NO.2 (SEE OVERHAUL
)
8.REMOVE HORN BUTTON ASSY (SEE OVERHAUL
)
9.REMOVE STEERING WHEEL ASSY (SEE OVERHAUL
)
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18001300150013000f00030013001c001c0018001700100013[5021)
10.REMOVE STEERING COLUMN COVER (SEE OVERHAUL
)
11.REMOVE SPIRAL CABLE SUB-ASSY (SEE REPLACEMENT
)
12.REMOVE TURN SIGNAL SWITCH ASSY (SEE REPLACEMENT
)
13.REMOVE INSTRUMENT PANEL SAFETY PAD GARNISH SUB-ASSY
a. Using a screwdriver, disengage the upper/lower 2 claws inside the instrument panel safety pad
garnish sub-assy.
HINT:
Tape up the screwdriver tip before use.

Fig. 40: Installing Instrument Panel Air Bag Assy Lower No.1
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
73.INSTALL SPIRAL CABLE SUB-ASSY (SEE REPLACEMENT
)
74.CENTER SPIRAL CABLE (SEE REPLACEMENT
)
75.INSTALL STEERING WHEEL ASSY (SEE OVERHAUL
)
76.STEERING WHEEL CENTER POINT
77.INSTALL HORN BUTTON ASSY (SEE OVERHAUL
)
78.CONNECT BATTERY NEGATIVE TERMINAL
79.INSPECT HORN BUTTON ASSY (SEE REPLACEMENT
)
80.INSPECT SRS WARNING LIGHT (SEE DIAGNOSIS SYSTEM
)
81.PERFORM INITIALIZATION (SEE INITIALIZATION
)
OVERHAUL
HINt: